Carbon dioxide levels
Last time CO2 levels were at 415ppm was 3 million years ago. Sea levels were around 80 feet higher and there was no ice at the poles. That is the scenario we are locked in currently.
Almost a quarter of the West Antarctic Ice Sheet can now be considered unstable, according to a new assessment of 25 years (1992-2017) of satellite data.
By unstable, scientists mean more ice is being lost from the region than is being replenished through snowfall.
Some of the biggest glaciers have thinned by over 120m in places.
Thwaites, and its neighbour Pine Island Glacier, appear to be the Achilles heel of the West Antarctic Ice Sheet.